In a medium saucepan, combine the sugar, water and mint. Bring to a boil, then simmer over medium heat, stirring occasionally, for about 5 minutes to make a mint-flavored simple syrup. Strain, discarding mint leaves, and cool. In a food processor, coarsely puree the berries. Turn into a bowl and stir in the wine and mint syrup. Taste and add lemon juice if you prefer a tarter flavor.
Pour the liquid into an ice cream maker and freeze according to manufacturer's directions until firm. Garnish with additional berries.
Makes: 1 1/2 quarts.